Package nl.vpro.util

Interface CountedIterator<T>

All Superinterfaces:

AutoCloseable, CloseableIterator<T>, Counted, Iterator<T>

All Known Subinterfaces:

CountedPeekingIterator<T>

All Known Implementing Classes:

BasicWrappedIterator, CallbackIterator, CountedMaxOffsetIterator, LazyIterator, MergedSortedIterator, TailAdder, WrappedIterator

public interface CountedIterator<T>
extends Iterator<T>, CloseableIterator<T>, Counted

An iterator that is also aware of the current position getCount(), and optionally of the size of the object that is iterated getSize(), and also optionally of a 'total' size (in case this iterator presents some sub-collection) getTotalSize().

Since:

0.31

Author:

Michiel Meeuwissen

Nested Class Summary

Nested classes/interfaces inherited from interface nl.vpro.util.CloseableIterator

CloseableIterator.WrappedCloseableIterator<S>, CloseableIterator.WrappedPeekingCloseableIterator<S>

Method Summary

Modifier and Type	Method	Description
default void	close()
Long	getCount()	The current position.
@NonNull Optional<Long>	getSize()	The size, if known, of the collection this iterator is representing
default @NonNull Optional<Long>	getTotalSize()	If the iterator is in some way restricted you may also want to report a total size, representing the unrestricted size.
static <C> CountedIterator<C>	of(Long size, Iterator<C> wrapped)
static <S> CountedIterator<S>	of(Collection<S> wrapped)
static <C> CountedIterator<C>	of(AtomicLong size, Iterator<C> wrapped)
static <S> CountedIterator<S>	of(Stream<S> wrapped)
default CountedPeekingIterator<T>	peeking()	If you need a guava PeekingIterator, this will make you one.
static <S> CountedPeekingIterator<S>	peeking(CountedIterator<S> wrapped)
default Spliterator<T>	spliterator()	Returns this iterator as Spliterator.
default Stream<T>	stream()

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Method Details

of

static <S> CountedIterator<S> of(Collection<S> wrapped)

peeking

static <S> CountedPeekingIterator<S> peeking(CountedIterator<S> wrapped)

of

static <S> CountedIterator<S> of(Stream<S> wrapped)

of

static <C> CountedIterator<C> of(Long size,
 Iterator<C> wrapped)

of

static <C> CountedIterator<C> of(AtomicLong size,
 Iterator<C> wrapped)

getSize

@NonNull Optional<Long> getSize()

The size, if known, of the collection this iterator is representing

getCount

Long getCount()

The current position. Will return 1 after first successfull call to Iterator.next(), 2 after the second one, and so on. It will return 0 before the first call.

Specified by:

getCount in interface Counted

getTotalSize

default @NonNull Optional<Long> getTotalSize()

If the iterator is in some way restricted you may also want to report a total size, representing the unrestricted size.

The default implementation is getSize().

spliterator

default Spliterator<T> spliterator()

Returns this iterator as Spliterator.

close

default void close()
            throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception

stream

default Stream<T> stream()

Specified by:

stream in interface CloseableIterator<T>

peeking

default CountedPeekingIterator<T> peeking()

If you need a guava PeekingIterator, this will make you one. It remains also a CountedIterator

Specified by:

peeking in interface CloseableIterator<T>